Adjustable reamer.



No. 892,871. I PATENTED JULY '7, 1908.'

F. B. MQGROSKY.

ADJUSTABLE REAMBR.

APPLICATION FILED JULY 29. 1907.

W5 [In coma FREDERICK B. MCOROSKY, OF ONTARIO, CALIFORNIA.

ADJUSTABLE REAMER.

Specification of Letters Patent.

Patented July 7, 1908.

Application filed July 29, 1907. Serial No. 385,972.

To all whom it may concern:

Be it known that I, FREDERICK B. McCRosKY, a citizen of the UnitedStates of America, and resident of Ontario, in the county of SanBernardino and State of California, have invented certain new and usefulImprovements in Adjustable Reamers, of which the following is aspecification.

This invention relates to certain new and useful improvements inadjustable reamer-s, and it has for its objects among others to providean adjustable reamer which will be capable of performing as satisfactorywork as a solid reamer.

The only practical adjustable reamer now on the market, so far as I amaware is the blade type but this does not permit of the employment ofenough blades or cutting edges by reason of inability to obtainsuflicient stren th in this style of adjustable reamer. T provide areamer which .overcomes these difficulties by making the entire shelladjustable and thus allowing as many teeth, either straight or spiral,as a solid reamer of the same size. Another and very important featureis the greater strength of such a construction of reamer over oneemploying narrow blades.

The invention is as applicable to an adjustable ta or an eX andingmandrel, as will be evident from t e following description.

My present improvement permits of the use of s iral teeth or cuttingedges. The adjustab e shell which completely surrounds the core is madein sections and is attached to the core in such a manner as to permit ofa lateral motion controlled by a threaded collar or by threaded collars,one at each end. Movement of the collar causes the sections of theadjustable shell to change their positions and thus the diameter of thecutting edges is increased or decreased at will, the dove-tail slotsbeing angular with relation to the center line of the core of thereamer.

Other objects and advantages of the invention will hereinafter ap ear,and the novel features thereof will e particularly pointed out in theappended claim.

ThlS invention, in its preferred form, is

clearly illustrated in the accompanying drawings, which, with thenumerals of reference marked thereon, form a part of this specificationand in which Figure 1 is a side elevation of a reamer constructed inaccordance with my invention. Fig. 2 is a substantially centrallongitudinal section thereof with parts in elevation. Fig. 3 is an endview looking in the direction of the arrow in Fig. 1.

Like numerals of reference indicate like parts throughout the severalviews.

Referring to the drawings :1 designates the core having a threaded shank2. This core 1 is provided with dove tail ribs 3 as shown clearly inFig. 3, the cross sectional contour of which may be as found mostexpedient. This core and the ribs or projections 3 are tapered from theouter end inward toward the shank as seen clearly in Fig. 2, and u onthese ribs or projections are mounted t e outer sections 4 constitutingthe outer shell of the reamer. These sections are provided with teeth orcutting edges 5 as seen best in Figs. 1 and 3 upon their peripheries soas to form a continuous series of cutting edges or teeth as will beevident from Figs. 1 and 3, giving to the reamer the outward appearanceof a solid reamer. The inner faces of these sections of the outer shellare provided with dove tail longitudinal grooves or recesses 6 toconform to the ribs or projections 3 with which they are engaged, asclearly illustrated in Fig. 3.

7 in Figs. 1 and 2 represents a threaded collar engaged with the screwthreaded shank and against which the back end of each of the sections 4of the outer shell rests. By moving this collar the sections are made tochange their positions and thus the diameter of the cutting edges isincreased or decreased at will, the dove tail grooves or recesses beingangular with the center line of the core or the inner sections of thereamer, as will be clearly understood. The incline or taper of theprojections and the corresponding recesses or grooves of the sections ofthe outer shell is clearly seen in Fig. 2.

It will thus be seen that I rovide a sectional adjustable outer shellwhich completely surrounds the core and is attached to the same in sucha manner as to permit of a lateral motion controlled by a threadedcollar. The teeth or cutting edges may be of any desired number, thesame as if the reamer were a solid one, and the reamer possessespractically the same strength as 1f it were made'solid. In lieu of thesingle collar herein shown, other means might be employed, for instancea threaded collar at each end such as is employed in the constructionshown in my Patent No. 826,109 issued July 17, 1906. In such case Imight employ a dove tail to hold the sections, or the threaded collarswould serve to hold the sections down, as well as serving foradjustment.

As will be clearly seen in Fig. 3, the outer faces of the ribs 3 arecurved to conform to the curvature of the outer sections 4, the bottomWalls of the grooves 6-being likewise curved: By this means, togetherwith the dovetailed construction hereinbefore described, the outersections are held down in close contact with the core and accidentaldisengagement in use is prevented. Furthermore, the contact surface ismaterially increased. Furthermore, the taper of the core increases fromthe end of the threaded shank outwardly toward the end where thediameter is the greatest, and the outer sections have a bearing on theadjacent threaded portion of said shank, as seen clearly in Fig. 2, thusgiving greater strength at the outer or free end of the reamer.

From the above it will be seen that I have devised a very simple yetdurable and efficient construction of adjustable reamer possessing allof the advantages of a solid reamer in addition to the desirable featureof ease of adjustment, and while the structural embodiment of theinvention as herein disclosed is what I at the present time considerpreferable, it is evident that the same is subject to chan es,variations and modifications without eparting tion or sacrificing any ofits advantages. I therefore do not wish to restrict myself to thedetails of construction herein disclosed, but reserve the right to makesuch changes, variations and modifications as come properly within thescope of the protection prayed.

What is claimed as new is A reamer having a core with dove tail inclined surfaces and of greater diameter at its outer end, a sectionalshell provided with peripheral cutting edges and normally completelysurrounding said core and having inclined undercut recesses to receivesaid surfaces, said recesses being angular with relation to the centerline of the core, and means from the spirit of the invenon the shank ofthe core for adjusting said shell.

Signed by me at Ontario, California, this 23d day of July, 1907FREDERICK B. MOCROSKY.

Witnesses:

E. H. RionARDsoN, C. W. NIoHoLs.

